This invention relates to a system and method for detecting overspeed conditions of a rotating member. While the invention is described with particular reference to its application in aircraft engines, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
A number of high performance aircraft employ engine electronic control means to supplement pilot input commands to a hydromechanical fuel control system for the engine. The electronic engine control means essentially is a special purpose computer which monitors the pilot throttle input and modifies those commands to obtain optimum engine, and consequently aircraft, performance. While the electronic engine control means works well for its intended purpose, the electronic engine control can malfunction. In particular, electronic engine control means can malfunction in a functional mode which results in full up trim commands being locked into the hydromechanical fuel control system. Thereafter, as the pilot advances the aircraft throttle, overspeed in the engine results, with subsequent engine destruction.
The overspeed detection system of this invention detects the impending overspeed condition, removes the electronic engine control commands, notifies the pilot of the sensed overspeed condition, and prevents the engine from being destroyed. The engine continues to be controlled by the basic hydromechanical fuel control system without assistance from the electronic engine control means.
The system of this invention is designed to be readily adaptable to existing aircraft models, and may be located in remote locations with respect to the engine and electronic engine control system being monitored. Because of its ability to be remotely located, the overspeed detection system of this invention may be installed in an environmentally acceptable portion of the aircraft, which enhances its reliability and decreases the maintenance required for the system.
One of the objects of this invention is to provide an overspeed detection system for a rotating device.
Another object of this invention is to provide an overspeed detection device for the turbine of an aircraft engine.
Another object of this invention is to provide an overspeed detection device which may be located remotely with respect to the rotating device being monitored.
Another object of this invention is to provide an overspeed detection system having built in test capabilities for checking system integrity.
Other objects of this invention will be apparent to those skilled in the art in light of the following description and accompanying drawings.